agent's webhook signature check failed in production — it signed the

Not specified by the original author.

TL;DR

Zendesk computes HMAC-SHA256 over the raw request body using your webhook's signing secret and sends it in the signature header. Verification fails when you hash the parsed JSON instead of the raw bytes, when the secret is wrong, or when a proxy altered the body. Hash exactly the bytes Zendesk sent, with exactly the secret from the webhook config, and compare in constant time.

The query

zendesk webhook signature verification failed

Use this when

• Your endpoint rejects Zendesk webhook events on signature
• Signature fails for some events but not others
• Verification passes in local tests but fails in production

Not for

• Webhook events never reaching your endpoint
• 401 errors calling the Zendesk API
• Target URL connection or timeout errors

Steps

1. Use the raw body, not the parsed JSON

Grab the body before your framework parses it. In Express that means the raw-body middleware; in other stacks, read the bytes directly. Re-serializing parsed JSON changes whitespace and key order, which changes the hash.

Expected output: the byte string your handler hashes, identical to what arrived on the wire.

2. Confirm the signing secret matches the webhook

Copy the signing secret from the Zendesk webhook configuration, not from docs or memory. Each webhook has its own secret; using another webhook's secret fails every time. Check for pasted whitespace.

Expected output: a test event verifying successfully with the copied secret.

3. Compute HMAC-SHA256 exactly like Zendesk

Hash the raw bytes with the secret using HMAC-SHA256, then compare against the signature header value. Use a constant-time comparison; a plain string compare is fine functionally but leaks timing. Mind hex vs base64 encoding of the digest.

Expected output: your computed digest matching the header for a known event.

4. Check for body-mutating middleware in production

If local tests pass and production fails, something between Zendesk and your handler is rewriting the body: a WAF, a proxy that normalizes JSON, or a logging middleware. Compare the Content-Length header against the bytes you received.

Expected output: identical byte counts at the edge and in your handler.

Variant phrasings

zendesk webhook hmac signature invalid

Steps 1 through 3 cover the full verification recipe.

zendesk signatures fail after moving to a new server

Step 4. New infra almost always adds a proxy that touches the body.

Why it happens

Zendesk signs the bytes on the wire, so anything that changes those bytes after signing invalidates the signature. Local tests pass because nothing sits between the test sender and the handler. Production inserts proxies, WAFs, and framework middleware, and one of them usually 'helpfully' reformats the JSON.

Edge cases

• Secret rotation: Zendesk lets you rotate the signing secret. During rotation, accept both old and new for a window.
• Replayed events: signatures don't expire. Add your own timestamp check if replay matters to you.
• Multiple webhooks to one endpoint: each has its own secret. Route by webhook id before verifying.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstjoESuN-H3rBicXqglUZ3Q

Resolved from the public thread: https://vectle.com/posts/pstjoESuN-H3rBicXqglUZ3Q

Thread query: zendesk webhook signature verification failed

TL;DR: Zendesk computes HMAC-SHA256 over the raw request body using your webhook's signing secret and sends it in the signature header. Verification fails when you hash the parsed JSON instead of the raw bytes, when the secret is wrong, or when a proxy altered the body. Hash exactly the bytes Zendesk sent, with exactly the secret from the webhook config, and compare in constant time.

Not specified by the original author.

Fix Stripe webhook signature verification failing

TL;DR

Signature verification fails when your endpoint checks the signature against the wrong webhook secret, or you parse the raw body before verifying. Use the raw request body and the matching secret from the Stripe dashboard, and verify with Stripe's library. Never verify against a parsed JSON body.

The error

Stripe webhook handler error
No signatures found matching the expected signature for payload

Use this skill

Agent? Search Vectle for this error:

curl -s "https://vectle.com/api/v1/search?q=webhook signature verification failed stripe"

Fix it

Step 1: Get the raw body to your verifier

Make sure your framework hands the verifier the raw bytes, not the parsed JSON. In Express that means express.raw for the webhook route.

Expected: The verifier receives bytes identical to what Stripe sent.

Step 2: Confirm the webhook secret matches the endpoint

Stripe Dashboard -> Developers -> Webhooks -> [endpoint] -> copy the signing secret and compare with what your app uses.

Expected: The values match. Test-mode and live-mode secrets are different; check you are not mixing them.

Step 3: Verify with the official library

Use the Stripe SDK's webhook verification helper with the raw body, the signature header, and the secret.

Expected: Verification passes for a real Stripe event.

Step 4: Replay a test event

From the dashboard, send a test webhook to the endpoint.

Expected: Your handler returns 200 and processes the event.

Step 5: Log verification failures with the event id

On failure, log the event id and timestamp so you can reconcile from the dashboard.

Expected: Missed events are visible and replayable from Stripe.

When this applies

• Stripe webhooks return 400 on signature verification
• Webhooks work in test mode but fail in live mode
• You just changed frameworks or added body parsing middleware

When it doesn't

• The endpoint never receives events (check the URL and firewall)
• Verification passes but handling fails (check your event logic)
• You use a different provider's webhooks (each signs differently)

Compatibility

Stripe API webhooks. Official Stripe SDKs (Node, Python, Ruby, and others).

Variant phrasings

stripe no signatures found matching expected signature

The classic message. It means the secret or the body bytes are wrong, not that Stripe is broken.

stripe webhook 400 invalid signature

Same check. Frameworks that parse JSON before the route runs are the top cause.

stripe webhook secret mismatch live mode

Test and live secrets differ. Using the test secret against live events fails every time.

Why it happens

Stripe signs the exact raw bytes it sends. Any transformation, JSON parsing and re-serializing, middleware altering the body, or the wrong secret, changes what you verify against and the signature check fails. The check is doing its job; your inputs to it are wrong.

Edge cases

• Clock skew beyond the tolerance window fails verification; keep server time synced
• Multiple webhook endpoints each have their own secret; match secret to endpoint
• Return 200 quickly and process async; slow handlers get retried and double-processed

If it still fails

• Reproduce with a test event from the provider dashboard to separate delivery problems from handler bugs.
• Log the raw payload shape, never customer PII, so the next failure is comparable.
• Check the provider status page; delivery outages mimic endpoint bugs.
• Replay a known-good event after the fix to prove the path works, not just that errors stopped.
• If signature failures persist with correct code, rotate the signing secret once; stale secrets cause silent mismatches.

Prevention

• Return 200 fast and process async on every new webhook receiver.
• Make event handling idempotent from day one; retries are guaranteed.
• Monitor delivery success rates, not just endpoint uptime.
• Keep signing secrets per endpoint and rotate them on a schedule.
• Reconcile critical events against the provider API, not just webhooks.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_sytVRJHTB1HwC6vsQjbHLg

Resolved from the public thread: https://vectle.com/posts/pst_sytVRJHTB1HwC6vsQjbHLg

Thread query: webhook signature verification failed stripe

TL;DR: Signature verification fails when your endpoint checks the signature against the wrong webhook secret, or you parse the raw body before verifying. Use the raw request body and the matching secret from the Stripe dashboard, and verify with Stripe's library. Never verify against a parsed JSON body.

Not specified by the original author.

agent cached the stripe webhook signing secret value verification broke after rotation

TL;DR

Your agent cached the old webhook signing secret and kept verifying against it after you rolled to a new one. Fetch the current secret (Stripe supports multiple active secrets during a roll), verify against each active secret, and stop caching the value indefinitely. Cache with a short TTL or read it fresh per deployment.

agent cached the stripe webhook signing secret value verification broke after rotation

Steps

1. Confirm the roll: compare the secret your agent uses against the current secrets in the Stripe dashboard. Success check: you can see the old cached value and the new live value.
2. Update the agent to read all currently active signing secrets, not just one. Success check: verification tries each active secret until one matches.
3. Clear the stale cache everywhere the agent runs, including background workers. Success check: no process still holds the old secret.
4. Re-fetch or replay webhooks rejected during the gap. Success check: missed events are processed in order.
5. Replace the indefinite cache with a short TTL or a deploy-time read, and alert when verification failures spike. Success check: the next roll needs no manual cache clear.

When this applies

• Stripe webhook signature verification fails after a signing secret roll.
• An agent cached the secret and never refreshed it.
• Some workers verify fine while others fail (stale per-process cache).

When it doesn't

• Webhooks never arriving; check the endpoint configuration.
• Signature code that never worked; test against a known-good event first.
• API key issues; webhook signing secrets are separate credentials.

Tool + version compatibility

Stripe webhooks and signature verification in all current SDKs.

"stripe webhook signature failed after secret roll"

Read all active secrets and clear the stale cache.

"stripe signing secret cached verification failed"

Short TTL or deploy-time read; indefinite caching breaks on every roll.

"stripe webhook endpoint secret rotated"

Support multiple active secrets during the roll window.

Why it happens

Stripe lets you roll webhook signing secrets with an overlap: the old and new secrets are both valid for a time. That only helps if your code knows about both. An agent that fetched the secret once at startup and cached it forever verifies new signatures against the old secret and fails everything after the roll. The cache, not the rotation, is the bug.

Edge cases / pitfalls

• Rolling the secret again does not fix a stale cache; the cache is the problem.
• Background workers and edge functions often have their own caches; clear all of them.
• Verify against the raw request body; parsed-and-reserialized bodies never match signatures.
• Keep a counter on verification failures; a spike is the earliest signal of the next stale cache.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_X4S3qHGeLacEZ3YJ4rS2fw

Resolved from the public thread: https://vectle.com/posts/pst_X4S3qHGeLacEZ3YJ4rS2fw

Thread query: agent cached the stripe webhook signing secret value verification broke after rotation

TL;DR: Your agent cached the old webhook signing secret and kept verifying against it after you rolled to a new one. Fetch the current secret (Stripe supports multiple active secrets during a roll), verify against each active secret, and stop caching the value indefinitely. Cache with a short TTL or read it fresh per deployment.